Spark plug and engine adopting spark plug

Abstract

The utility model discloses a spark plug and an engine adopting the spark plug, the spark plug comprises a central electrode and a grounding electrode surrounding the central electrode, the central electrode is basically cylindrical, the grounding electrode comprises a side electrode, the side electrode is close to the central electrode and forms a grounding cambered surface, the grounding cambered surface is parallel to the side surface of the central electrode, and the side surface of the central electrode is parallel to the grounding cambered surface. And the central electrode is electrically connected with the grounding cambered surface. Through the arrangement, the corrosion resistance of the grounding cambered surface and the side surface of the central electrode can be improved, and the service life of the spark plug is further prolonged.

Description

Technical Field

[0001] The present application relates to the fields of ignition devices and power devices, and in particular to a spark plug and an engine using the spark plug. Background Art

[0002] At present, spark plugs can be used as ignition devices of engines. The electric sparks generated by the spark plugs can ignite the mixed combustible gas so that the crank-connecting rod mechanism of the engine can rotate normally, thereby achieving stable operation of the engine.

[0003] In the related art, the spark plug includes a center electrode and a side electrode, wherein most of the side electrodes are linear near the center electrode, and the center electrode and the side electrodes are easily eroded by electric sparks, resulting in damage to the center electrode and the side electrodes, thereby reducing the service life of the spark plug. Utility Model Content

[0004] In order to address the deficiencies of the prior art, the purpose of the present application is to provide a spark plug and an engine using the spark plug, wherein the spark plug has a long service life.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] A spark plug includes a center electrode and a ground electrode. The center electrode is basically cylindrical. The ground electrode is arranged around the center electrode. The ground electrode includes a side electrode. The side electrode is close to the center electrode and forms a ground arc surface. The ground arc surface is parallel to the side surface of the center electrode. The center electrode is electrically connected to the ground arc surface.

[0007] Furthermore, along the axial direction of the center electrode, the axis of the center electrode substantially coincides with the axis of the grounding arc surface, and the distance between the side surface of the center electrode and the grounding arc surface ranges from 0.6 mm to 1.1 mm.

[0008] Furthermore, a precious metal ring is sleeved on the center electrode, the melting point of the precious metal ring is greater than the melting point of the center electrode, and the center electrode is electrically connected to the grounding arc surface through the precious metal ring; wherein, the precious metal ring is in a circular ring shape, and the outer diameter of the precious metal ring is basically equal to or greater than the outer diameter of the center electrode.

[0009] Furthermore, at least a portion of the side surface of the center electrode is recessed inward to form a triangular limiting groove, the triangular limiting groove is arranged around the circumference of the center electrode, and the noble metal ring is sleeved in the triangular limiting groove.

[0010] Furthermore, the number of the side electrodes is two, the two side electrodes are arranged around the circumference of the central electrode, and the two side electrodes are centrally symmetrical about the axis of the central electrode.

[0011] Furthermore, the number of the side electrodes is three, the three side electrodes are arranged circumferentially around the central electrode, and the distance between two adjacent side electrodes is substantially the same.

[0012] Furthermore, a precious metal sheet is installed on the ground arc surface, the melting point of the precious metal sheet is higher than the melting point of the side electrode, and the center electrode is electrically connected to the side electrode through the precious metal sheet.

[0013] Furthermore, the spark plug also includes a ceramic sleeve and a high-voltage terminal. The high-voltage terminal is located above the center electrode and is electrically connected to the center electrode. The high-voltage terminal and the center electrode are at least partially located in the ceramic sleeve. The ground electrode is sleeved on the ceramic sleeve.

[0014] Furthermore, the central electrode is configured to be an iridium alloy or a platinum alloy, and the side electrodes are configured to be a platinum alloy.

[0015] An engine comprises any one of the aforementioned spark plugs.

[0016] The above-mentioned spark plug can arrange the grounding arc surface and the side of the center electrode in parallel to increase the arc surface area for generating electric sparks, thereby improving the corrosion resistance of the grounding arc surface and the side of the center electrode to avoid erosion by electric sparks, which is beneficial to improving the service life of the spark plug. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A front view of a spark plug provided in accordance with an embodiment of the present application.

[0018] Figure 2 for Figure 1 Cross-sectional view along the XX direction.

[0019] Figure 3 A bottom view of a spark plug of an engine provided in an embodiment of the present application.

[0020] Figure 4 for Figure 2 A partial enlarged view of point A in the middle.

[0021] Figure 5 This is a schematic diagram of the overall structure of the spark plug provided in an embodiment of the present application when installed in an engine.

[0022] Figure 6 for Figure 5 A partial exploded view of the engine.

[0023] Figure 7 A cross-sectional view of the engine's cylinder head and ignition device. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation of the present application will be clearly and completely described below in conjunction with the drawings in the implementation of the present application.

[0025] like Figure 1 and Figure 2 As shown, a spark plug 171 includes a center electrode 1711 and a ground electrode 1712. Specifically, center electrode 1711 is substantially cylindrical, and ground electrode 1712 is disposed around center electrode 1711. Ground electrode 1712 includes side electrodes 1712a. Side electrodes 1712a are adjacent to center electrode 1711 and have ground arc surfaces 1712b formed thereon. Ground arc surfaces 1712b are parallel to the side surfaces of center electrode 1711, and center electrode 1711 is electrically connected to ground arc surfaces 1712b.

[0026] like Figure 3 As shown, more specifically, a small spark gap 1713 exists between the center electrode 1711 and the side electrode 1712a. Under the action of high voltage on the spark plug 171, the air within the spark gap 1713 rapidly ionizes, forming positively charged ions and negatively charged free electrons. When the voltage between the electrodes reaches a certain value, the number of ions and electrons in the gas increases rapidly, causing the air to lose its insulating properties. Spark gap 1713 then forms a discharge channel, resulting in a "breakdown" phenomenon. At this point, the gas forms a luminous body, or "spark." Furthermore, due to the high temperature of the spark, the present application configures the grounding arc surface 1712b and the side surface of the center electrode 1711 as parallel curved surfaces. This increases the area of ​​the grounding arc surface 1712b and the side surface of the center electrode 1711, thereby increasing the effective spark gap 1713 and, therefore, the volume of the discharge channel. Through the above arrangement, the corrosion resistance of the ground arc surface 1712 b and the side surface of the center electrode 1711 can be improved to avoid erosion by electric sparks, thereby facilitating the improvement of the service life of the spark plug 171 .

[0027] like Figure 3As shown, as an implementation, along the axis of the center electrode 1711, the axis of the center electrode 1711 substantially coincides with the axis of the grounding arc surface 1712b, and the minimum distance D1 between the side surface of the center electrode 1711 and the grounding arc surface 1712b ranges from 0.5 mm to 1.2 mm. Furthermore, the minimum distance D1 between the side surface of the center electrode 1711 and the grounding arc surface 1712b ranges from 0.6 mm to 1.1 mm. Furthermore, the minimum distance D1 between the side surface of the center electrode 1711 and the grounding arc surface 1712b ranges from 0.7 mm to 0.9 mm. Through the above-mentioned setting, it is possible to avoid the spark plug 171 from having difficulty in generating sparks due to the minimum distance D1 between the side of the center electrode 1711 and the grounding arc surface 1712b being too large, thereby preventing the spark from being unable to normally burn the combustible gas between the side of the center electrode 1711 and the grounding arc surface 1712b, thereby helping to improve the working stability of the spark plug 171; it is also possible to avoid the spark plug 171 from having too high a temperature generating the spark due to the minimum distance D1 between the side of the center electrode 1711 and the grounding arc surface 1712b being too small, thereby preventing the spark from damaging the side of the center electrode 1711 and the grounding arc surface 1712b, thereby helping to improve the service life of the spark plug 171.

[0028] It should be noted that the area of ​​the ground arc surface 1712b is 3mm 2 Up to 7mm 2 Specifically, the area of ​​the ground arc surface 1712b is 4mm 2 Up to 6mm 2 More specifically, the area of ​​the ground arc surface 1712b is 5mm 2 The above arrangement can avoid the side electrode 1712a from being too large due to the grounding arc surface 1712b being too large, thereby preventing the side electrode 1712a from interfering with the contact area between the electric spark and the mixed combustible gas, thereby facilitating improved combustion efficiency of the mixed combustible gas. Furthermore, the reduction in the corrosion resistance of the side electrode 1712a due to the grounding arc surface 1712b being too small can be avoided, thereby preventing the side electrode 1712a from being reduced in service life, thereby facilitating improved service life of the spark plug 171.

[0029] like Figure 4As shown, as one implementation, a precious metal ring 1714 is sleeved over the center electrode 1711. The melting point of precious metal ring 1714 is greater than that of center electrode 1711, and center electrode 1711 is electrically connected to ground arc surface 1712b via precious metal ring 1714. Specifically, precious metal ring 1714 has excellent corrosion resistance. Since the corrosion resistance of center electrode 1711 is much lower than that of precious metal ring 1714, precious metal ring 1714 is sleeved over center electrode 1711, and electric sparks are generated on precious metal ring 1714. This arrangement prevents electric sparks from eroding center electrode 1711, thereby extending the service life of center electrode 1711 and, in turn, improving the service life of spark plug 171. It should be noted that precious metal ring 1714 may be a synthetic metal such as gold, silver, iridium, or platinum.

[0030] In this embodiment, the side surface of center electrode 1711 is at least partially recessed inward to form a triangular retaining groove 1711a. Triangular retaining groove 1711a is arranged circumferentially around center electrode 1711, and precious metal ring 1714 is sleeved within triangular retaining groove 1711a. Specifically, triangular retaining groove 1711a restricts the axial movement of precious metal ring 1714 along center electrode 1711, thereby further stabilizing the connection between precious metal ring 1714 and center electrode 1711. This arrangement enhances the connection strength between precious metal ring 1714 and center electrode 1711, thereby improving the structural and operational stability of spark plug 171.

[0031] Exemplarily, the precious metal ring 1714 is in the shape of a circular ring, and the outer diameter of the precious metal ring 1714 is substantially equal to or greater than the outer diameter of the center electrode 1711. The above arrangement can enable electric sparks to always be generated on the precious metal, thereby avoiding electric sparks generated on the center electrode 1711 and causing erosion of the center electrode 1711, thereby helping to improve the service life of the center electrode 1711.

[0032] As an implementation, there are two side electrodes 1712a, which are arranged circumferentially around the center electrode 1711 and are centrally symmetrical about the axis of the center electrode 1711. Specifically, because electric sparks will alternately erode either of the two side electrodes 1712a, when the spark gap 1713 between one side electrode 1712a and the precious metal ring 1714 is smaller than the spark gap 1713 between the other side electrode 1712a and the precious metal ring 1714, the electric spark will be generated between the side electrode 1712a with the smaller spark gap 1713 and the precious metal ring 1714. Therefore, the electric spark will continuously change its generation position to evenly consume the two side electrodes 1712a, thereby extending the service life of the side electrodes 1712a and thereby facilitating the improvement of the service life of the spark plug 171. It should be noted that the two side electrodes 1712a are centrally symmetrical about the axis of the central electrode 1711, which can prevent the electric spark from always eroding a certain part of the precious metal ring 1714, thereby helping to increase the overall service life of the precious metal ring 1714, and further helping to increase the service life of the spark plug 171.

[0033] As another implementation, there are three side electrodes 1712a, which are arranged circumferentially around the center electrode 1711, and the distance between two adjacent side electrodes 1712a is substantially uniform. Specifically, because the electric spark will alternately erode any one of the three side electrodes 1712a, when the spark gap 1713 between one side electrode 1712a and the precious metal ring 1714 is smaller than the spark gap 1713 between another side electrode 1712a and the precious metal ring 1714, the electric spark will be generated between the side electrode 1712a with the smaller spark gap 1713 and the precious metal ring 1714. Therefore, the electric spark will continuously change its generation position to achieve uniform consumption of the three side electrodes 1712a, thereby extending the service life of the side electrodes 1712a and thereby facilitating the improvement of the service life of the spark plug 171. It should be noted that the distance between two adjacent side electrodes 1712a is substantially the same, thereby preventing the electric spark from always eroding a certain part of the noble metal ring 1714, which is beneficial to improving the overall service life of the noble metal ring 1714 and further beneficial to improving the service life of the spark plug 171.

[0034] It should be noted that the number of the side electrodes 1712 a can be adjusted according to actual needs to increase the service life of the side electrodes 1712 a.

[0035] As an implementation, a precious metal sheet 1715 is mounted on the grounding arc surface 1712b. The melting point of the precious metal sheet 1715 is higher than that of the side electrode 1712a. The center electrode 1711 is electrically connected to the side electrode 1712a via the precious metal sheet 1715. Specifically, an electric spark can be generated between the precious metal sheet 1715 and the precious metal ring 1714, i.e., the spark gap 1713 is located between the precious metal sheet and the precious metal ring 1714. The precious metal sheet 1715 and the precious metal ring 1714 have the same corrosion resistance, effectively preventing erosion caused by the electric spark. This arrangement can extend the service life of the side electrode 1712a, while the precious metal ring 1714 can extend the service life of the center electrode 1711, thereby increasing the service life of the spark plug 171. It should be noted that the precious metal sheet 1715 can be a synthetic metal such as gold, silver, iridium, or platinum.

[0036] As another implementation, both the center electrode 1711 and the side electrode 1712a are constructed from precious metals. This configuration can improve the overall strength of the center electrode 1711 and the side electrode 1712a, thereby preventing localized erosion of the center electrode 1711 and the side electrode 1712a by sparks, thereby improving the overall life of the spark plug 171. It should be noted that the center electrode 1711 can be constructed from an iridium alloy or a platinum alloy, and the side electrode 1712a can be constructed from a platinum alloy.

[0037] like Figure 5 and Figure 6An engine 100 is shown, comprising a housing 11, a crank-connecting rod mechanism 12, a transmission mechanism 13, a valve train 14, a starting mechanism 15, and a lubrication mechanism 16. The housing 11 forms the basic framework of the engine 100, and defines a housing space 101 therein for accommodating and protecting the internal components of the engine 100. The housing 11 comprises a cylinder head cover 111, a cylinder head 112, a cylinder block 113, a crankcase 114, an oil pan 115, and a transmission 116. The cylinder head cover 111, cylinder head 112, cylinder block 113, crankcase 114, and oil pan 115 are sequentially connected, and the transmission 116 is connected to the crankcase 114. The housing space 101 is essentially formed by the interconnected cylinder head cover 111, cylinder head 112, cylinder block 113, crankcase 114, oil pan 115, and transmission 116. The crank-connecting rod mechanism 12 is at least partially disposed within the crankcase 114 and includes a crankshaft 121 and a connecting rod assembly 122 connected to the crankshaft 121. The crankshaft 121 is located within the crankcase 114 and is rotationally connected thereto. The connecting rod assembly 122 is at least partially located within the crankcase 114 and at least partially within the cylinder block 113. The speed change mechanism 13 is located within the transmission case 116 and is in driving connection with the crankshaft 121. The valve mechanism 14 is at least partially disposed within the accommodating space 101 and is in driving connection with the crankshaft 121. The starting mechanism 15 is located outside the crankcase 114 and is connected thereto. The starting mechanism 15 at least partially passes through the crankcase 114 and is in driving connection with the crankshaft 121. The lubrication mechanism 16 is at least partially located in the oil pan 115, and the lubrication mechanism 16 is arranged through the cylinder head 112, the cylinder block 113 and the crankcase 114 to achieve lubrication of the components inside the housing 11. When the engine 100 is working, the fuel and air are mixed into a combustible mixture and then transported to the combustion chamber 1120 of the engine 100. After the combustible mixture burns, a large amount of heat is released, and the gas pressure and temperature in the cylinder block 113 rise rapidly, thereby driving the connecting rod assembly 122 to move. Among them, the combustion chamber 1120 of the engine 100 is composed of the bottom of the cylinder head 112 and the top of the cylinder block 113. The crankshaft 121 is connected to the connecting rod assembly 122, and the movement of the connecting rod assembly 122 can drive the crankshaft 121 to move, so that the crank-connecting rod mechanism 12 can output power. In order to clearly illustrate the technical solution of the present application, it is also defined as follows Figure 5The front, rear, left, right, top, and bottom are shown. It will be understood that in the embodiment of the present application, the front-to-back direction refers to the length direction of the engine 100, the left-to-right direction refers to the width direction of the engine 100, and the top-to-bottom direction refers to the height direction of the engine 100. Among them, the cylinder head cover 111, the cylinder head 112, the cylinder block 113, the crankcase 114, and the oil pan 115 are basically distributed in the top-to-bottom direction, that is, the crankcase 114 is arranged on the upper side of the oil pan 115, the cylinder block 113 is arranged on the upper side of the crankcase 114, the cylinder head 112 is arranged on the upper side of the cylinder block 113, and the cylinder head cover 111 is arranged on the upper side of the cylinder head 112.

[0038] It should be noted that the center electrode 1711 and the ground electrode 1712 are at least partially located in the combustion chamber 1120 , and the side electrode 1712 a is located in the combustion chamber 1120 .

[0039] like Figure 7 As shown, as an implementation method, the engine 100 also includes an ignition device 17, which includes the above-mentioned spark plug 171 and an igniter 172. The spark plug 171 is located in the cylinder head 112, and the igniter 172 is at least partially located in the cylinder head 112. The igniter 172 is electrically connected to the spark plug 171. The ignition device 17 can generate electric sparks with sufficient energy at regular intervals to generate electric sparks between the two electrodes of the spark plug 171, thereby igniting the combustible mixture and driving the engine 100 to operate normally. Specifically, an ignition hole 1121 is opened on the cylinder head 112, the spark plug 171 passes through the ignition hole 1121 and is at least partially located in the combustion chamber 1120, the igniter 172 is at least partially located in the ignition hole 1121, and the igniter 172 is sleeved on the upper part of the spark plug 171. The igniter 172 is used to provide electrical energy to the spark plug 171 so that the spark plug 171 generates an electric spark, thereby realizing normal operation of the engine 100.

[0040] like Figure 2 As shown, as an implementation, the ignition device 17 further includes a ceramic sleeve 173 and a high-voltage terminal 174. Along the height of the engine 100, the high-voltage terminal 174 is located above and electrically connected to the center electrode 1711. Both the high-voltage terminal 174 and the center electrode 1711 are at least partially located within the ceramic sleeve 173, and the ground electrode 1712 is sleeved on the ceramic sleeve 173. Specifically, the ceramic sleeve 173 is insulating, so positioning the ceramic sleeve 173 between the ground electrode 1712 and the center electrode 1711 prevents contact and electrical conduction between the ground electrode 1712 and the center electrode 1711, thereby facilitating the formation of an electric spark between the center electrode 1711 and the side electrode 1712a. This arrangement improves the operating stability of the center electrode 1711 and the ground electrode 1712, thereby improving the operating stability of the spark plug 171.

[0041] In this embodiment, the upper portion of the ceramic sleeve 173 is configured as a bellows structure. Specifically, since the ignition hole 1121 is connected to the outside world, when the engine 100 is eroded by rainwater, rainwater can enter the gap between the spark plug 171 and the ignition hole 1121 through the ignition hole 1121. Since rainwater is conductive, it increases the risk of the end of the high-voltage terminal 174 away from the center electrode 1711 connecting to the ground electrode 1712. Therefore, the present application provides a bellows structure at the upper portion of the ceramic sleeve 173, and the bellows structure can be tightly abutted against the ignition hole 1121, thereby preventing rainwater from entering the gap between the spark plug 171 and the ignition hole 1121. Through the above configuration, the sealing performance of the ignition device 17 and the cylinder head 112 can be improved, thereby improving the sealing performance of the engine 100, preventing the engine 100 from failing to start, and further improving the operating stability of the engine 100.

[0042] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the claims appended to this application.

Claims

1. A spark plug, include: a central electrode, the central electrode being substantially cylindrical; a ground electrode, the ground electrode being arranged around the central electrode; It is characterized by: The ground electrode includes a side electrode, the side electrode is close to the central electrode and is formed with a ground arc surface, the ground arc surface is parallel to the side surface of the central electrode, and the central electrode is electrically connected to the ground arc surface.

2. The spark plug according to claim 1, wherein Along the axial direction of the central electrode, the axis of the central electrode substantially coincides with the axis of the grounding arc surface, and the distance between the side surface of the central electrode and the grounding arc surface ranges from 0.6 mm to 1.1 mm.

3. The spark plug according to claim 1, wherein A precious metal ring is sleeved on the center electrode, the melting point of the precious metal ring is greater than the melting point of the center electrode, and the center electrode is electrically connected to the grounding arc surface through the precious metal ring; wherein, the precious metal ring is in a circular ring shape, and the outer diameter of the precious metal ring is basically equal to or greater than the outer diameter of the center electrode.

4. The spark plug according to claim 3, wherein: The side surface of the central electrode is at least partially recessed inward to form a triangular limiting groove. The triangular limiting groove is arranged around the circumference of the central electrode, and the noble metal ring is sleeved in the triangular limiting groove.

5. The spark plug according to claim 3, wherein: The number of the side electrodes is two, the two side electrodes are arranged around the circumference of the central electrode, and the two side electrodes are centrally symmetrical about the axis of the central electrode.

6. The spark plug according to claim 3, wherein: The number of the side electrodes is three, and the three side electrodes are arranged circumferentially around the central electrode, and the distance between two adjacent side electrodes is substantially the same.

7. The spark plug according to claim 3, wherein: A precious metal sheet is mounted on the ground arc surface. The melting point of the precious metal sheet is higher than that of the side electrode. The center electrode is electrically connected to the side electrode via the precious metal sheet.

8. The spark plug according to claim 1, wherein The spark plug also includes a ceramic sleeve and a high-voltage terminal. The high-voltage terminal is located above the center electrode and is electrically connected to the center electrode. The high-voltage terminal and the center electrode are at least partially located in the ceramic sleeve. The ground electrode is sleeved on the ceramic sleeve.

9. The spark plug according to claim 1, wherein The central electrode is configured to be an iridium alloy or a platinum alloy, and the side electrodes are configured to be a platinum alloy.

10. An engine, characterized in that: The engine comprises the spark plug according to any one of claims 1 to 9.

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